Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
  • F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means
  • F01L9/22—Valve-gear or valve arrangements actuated non-mechanically by electric means actuated by rotary motors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
  • F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means

Definitions

• the present invention relates to an apparatus and a method for controlling the Hubverlaufes an exhaust gas exchange valve of an internal combustion engine according to the preamble of the independent claims.
• the camshaft is mechanically driven via a timing chain or timing belt from the crankshaft.
• a so-called electromagnetic valve train In the case of a fully variable valve train, an "actuator unit" is assigned to each valve or "valve group" of a cylinder.
• actuator units In a basic type (so-called stroke actuators), a valve or a valve group is associated with an opening and a closing magnet. By energizing the magnets, the valves can be displaced axially, i. be opened or closed.
• a control shaft is provided with a cam, wherein the control shaft is pivotable by an electric motor back and forth.
• a Drehaktuatorvorraum for stroke control of a gas exchange valve is described.
• the stroke control takes place here via a map-controlled electric motor, to whose rotor a shaft is arranged with a rotatably connected control cam.
• the motor oscillates or reciprocates and the control cam periodically presses the gas exchange valve into its open position via a pivoting lever.
• the gas exchange valve is closed by the spring force of a valve spring.
• an additional spring is attached to the shaft.
• the forces of valve spring and additional spring are such that during periodic operation of the rotary actuator device according to the position of the gas exchange valve, the kinetic energy is stored either in the valve spring or in the additional spring.
• the object of the invention is to provide a device for controlling the Hubverlaufes an exhaust gas exchange valve, which ensures an improvement in terms of electrical energy consumption of an actuator.
• the opening operation of the outlet valve takes place to the desired extent in each operating state.
• the object is achieved by the entirety of the features of claim 1.
• at least two set paths are provided for controlling the speed of the rotor of an electric cylinder driving an exhaust gas exchange valve.
• the nominal paths differ in that they generate different high kinetic energies due to their design and the associated acceleration of the rotor during the valve opening operation and transmitted via the actuator connected to the rotor to the outlet gas exchange valve.
• At least one first setpoint path is provided for generating and transmitting a lower kinetic energy, wherein the setpoint path is used when, for example, due to a smaller current load or load requirement (load within a predetermined load range of lower load) a smaller gas back pressure prevails in the combustion chamber.
• at least one second desired path is provided, which is the generation and transmission of a compared to Kinetic energy of the first setpoint path generates and transmits increased kinetic energy.
• the kinetic energy component is generated by using a second setpoint trajectory, the rotor angular velocity - at least in the Wegphase to the vertex of the Hubverlaufes the outlet gas exchange valve (in particular a predetermined period before the start of the valve movement, ie during the so-called freewheeling phase of the actuating element) - during the opening process is increased in comparison with the rotor angular velocity (in the same path phase or in the same time period) in regulation according to the first nominal path.
• the second desired path either from the beginning of the route (of the rotor) (and thus a defined time before the start of the actual valve movement) or from a predetermined time or a certain distance (of the rotor) (also a defined time before the start of the actual valve movement) increases the speed specification for the rotor in comparison to the speed specification according to the first desired path such that in the freewheeling phase of the rotor an increased kinetic energy in comparison with the first desired path is generated.
• the invention finds its application in rotary actuator systems with an electric cam drive, in which the cam drive driving the exhaust gas exchange valve and driven via the rotor of the electric motor has a freewheeling section.
• the freewheeling section ensures that the rotor, starting from the closing position of the outlet gas exchange valve, in which the rotor with the smallest stroke - in particular the zero stroke predetermined by the cam base circle - acts on the outlet gas exchange valve, for a defined run-up section on the Cam base circle moves.
• the cam actuator Over the entire path of the Anlaufwegabiteses the cam actuator can be accelerated with the lowest energy consumption by the electric motor and thus generated kinetic energy for transmission to the outlet gas exchange valve.
• Figure 1 the schematic representation of a Drehaktuatorvorraum for driving a gas exchange valve of a not shown
• FIG. 1 shows a schematic representation of a rotary actuator device for driving an outlet gas exchange valve 2 (referred to below as the gas exchange valve) of an internal combustion engine (not shown).
• the essential components of this device are, in particular designed as a servomotor electric motor 4 (drive means), a driven by this, preferably two cams 6a, 6b different strokes camshaft 6 (actuator), one with the camshaft 6 on the one hand and with the gas exchange valve 2 on the other operatively connected rocker arm 8 (transmission element) for transmitting movement of the predetermined by the cam 6a, 6b lifting height to the gas exchange valve 2 and one, the gas exchange valve 2 in the closing direction with a spring force acting and designed as a closing spring first energy storage means 10 and, via the camshaft 6 and the drag lever 8, the gas exchange valve 2 acted upon by an opening force and designed as an opening spring second energy storage means 12.
• a servomotor electric motor 4 drive means
• actuator driven by this, preferably two cams 6a, 6b different strokes camshaft 6 (actuator)
• actuator cams 6a, 6b different strokes camshaft 6
• the gas exchange valve 2 on the other operatively connected rocker
• the electric motor 4 via a control device 20 according to a desired path, which maps the ideal swing-out behavior of the spring-mass-spring system regulated.
• this control is done by controlling the rotor profile of the, the at least one actuator 6, 6a, 6b driving electric motor 4.
• the ideal path of the rotor, which resonates as part of the vibration system is calculated analogously to the ideal waveform of the overall system and forms the Target path for controlling the electric motor 4.
• a not shown displacement sensor is present, which transmits a sensor signal S to the control device 20 or another control device.
• the electric motor 4 is controlled by the control device 20 such that the at least one gas exchange valve 2 from a first Ventilendlage E1, which corresponds for example to the closed valve position, in a second Ventilendlage E2, E2 ', for example, a partial (E2 1 : Generalhub) or maximum opened (E2: full stroke) valve position corresponds, is transferred and vice versa.
• the system is ideally designed so that the actuator 6, 6a, 6b in the exclusion (targeted disregard) of the environmental influences (in particular friction and gas back pressure) the way between two end positions R1 - R2 (full stroke) or R1 '- R2' (partial stroke) without Infeed additional energy, ie without active drive by the drive device 4, travels and thus engages supportive only in the environmental conditions occurring in practice.
• the system is preferably designed in such a way that in the maximum end positions R1, R2 of the rotor (oscillation end positions at maximum oscillation stroke) each is in a torque-neutral position, in which the forces occurring are in an equilibrium of forces and in which the rotor without application of an additional Holding force is held.
• the gas exchange valve 2 in the first torque-neutral position R1 (shown in FIG. 1) the gas exchange valve 2 is closed and thus the closing spring 10 while maintaining a residual preload maximum relaxed while the opening spring 12 is biased to the maximum.
• the force of the prestressed opening spring 12 is transmitted to the camshaft 6 via a stationary support element 6c and is directed in the position R1 exactly through the center of the camshaft 6 and thus virtually neutralized.
• the existing due to the residual bias force of the closing spring 10 is neutralized in the described position, as this is also directed via the cam followers 8 in the center of the camshaft 6.
• the gas exchange valve 2 In the second torque-neutral position R2, not shown, the gas exchange valve 2 would be opened with its maximum stroke according to the main cam 6b and the gas exchange valve 2 arranged around the closing spring 10 maximum biased while the opening spring 12 would be maximally relaxed while maintaining a residual bias.
• the arrangement of the individual components is chosen such that again the force of the maximum prestressed spring means (now: closing spring 10) and the maximum relaxed spring means (now: opening spring 12) respectively directed through the center of the camshaft 6 and thus virtually neutralized in this position are.
• a third, also not shown, torque-neutral position RO is present when the system assumes a so-called dropped state in which the camshaft 6 assumes a position between the two first torque-neutral positions R1, R2. From the fallen position, the system can be brought out again only by high energy expenditure, in which, for example, by swinging or swinging the rotor, the camshaft 6 is again transferred to one of the two first torque-neutral positions R1, R2 or the camshaft 6 at least up to a partial stroke is swung, in which a regular operation of the rotary actuator device is possible again.
• the rotor thus oscillates from one end position E1, E1 'into the other end position E2, E2' solely on the basis of the forces stored in the energy storage means 10, 12 without the introduction of additional energy, for example by the electric motor 4.
• FIG. 2 a shows schematically the desired specification of a speed profile for the rotor of an electric motor 4 for actuating an outlet gas exchange valve 2.
• the setpoint path SB1 shown in bold is a setpoint path for controlling the rotor speed on the basis of which is to be controlled when only lower gas back pressures within the combustion chamber during the opening operation of the outlet gas exchange valve 2 are present or expected.
• the second target web SB2, which is not shown in bold, is a target web in the event that increased gas counterpressures are present or to be expected in the combustion chamber, so that this target web has an increased speed specification for the rotor, in particular in the travel range shortly before the actual valve opening movement of the exhaust Gas exchange valve 2, pretends.
• the rotor speed is thereby increased such that by means of the second setpoint path SB2 a kinetic energy Ekin_beschieunigt increased compared and can be transmitted to the outlet gas exchange valve 2.
• the speed specification based on the second setpoint path SB2 can be either over the entire travel range of the rotor and at any time - compared to the first desired course - be increased, or increased only over individual parts of the path range.
• dam i in a defined period of time .DELTA.t e UNIG t before the start of valve opening movement (at point released), the rotor speed is increased selectively.
• Both the period ⁇ tbesh h e eigt as well as the amount of acceleration are preferably given as a function of the particular load request present.
• the speed of the rotor in the starting phase of the rotor accordingly lower than in the desired path for a lower or an average load request.
• the increase in speed results in an increase in the kinetic energy which ensures that gas back pressures occurring at every operating time can be overcome during the opening process of the outlet gas exchange valve 2.
• a plurality of setpoint paths for controlling the rotor speed are present, wherein each setpoint path is assigned a predetermined load range or a predetermined gas backpressure range.
• additional nominal paths can be generated by interpolation in a region between two adjacent stored nominal paths.
• FIG. 2b in each case shows the rotor angle of the electric motor 4 which adjusts due to the regulation of the rotor angular velocity.
• the curve segment shown by dashed lines is the rotor angle profile due to the increased rotor angular velocity. Accordingly, the increased rotor angular velocity leads analogously directly to an increased rotor angle.
• the early increased rotor angle does not lead to an immediate output of the gas exchange valve 2 due to the freewheeling section described above, but allows in the manner of the invention the construction of an additional kinetic energy E kin accelerated (by acceleration of moving during the freewheel masses, such as rotor mass and mass of the actuating element) for assisting the electric motor 4 during the opening operation of the exhaust gas exchange valve 2.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve Device For Special Equipments (AREA)
• Characterised By The Charging Evacuation (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=35709014

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Family Cites Families (4)

• 2004
  • 2004-11-12 DE DE102004054775A patent/DE102004054775B4/de not_active Expired - Fee Related
• 2005
  • 2005-10-19 EP EP05803031A patent/EP1812693B1/fr not_active Not-in-force
  • 2005-10-19 AT AT05803031T patent/ATE445086T1/de not_active IP Right Cessation
  • 2005-10-19 DE DE502005008295T patent/DE502005008295D1/de active Active
  • 2005-10-19 WO PCT/EP2005/011246 patent/WO2006050795A1/fr active Application Filing
• 2007
  • 2007-05-10 US US11/798,163 patent/US7753015B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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